Question

In Procedure 1: a wire of length L = 3.91 cm sits on an electronic
scale. There is also a uniform mangetic field perpendicular to the
wire, and along its entire length. When there is no current in the
wire, the scale reads 573 g. When a current I = 48.2 mA goes
through the wire, and the scale reads 544 g.
NOTE: Beware of units!

a) Find F, the magnitude of the force on the wire created by the
interaction of the current and the magnetic field.
____ N

b) Find B, the magnitude of the magnetic field around the
wire.
_________T

c) Suppose the direction of the magnetic field is reversed. What
would the scale read now?
___________ g

d) Suppose the system could take large currents. To what would you
have to raise the current (before you reversed the direction of B)
so the force on the wire entirely supported the weight of the wire
(and the scale reads zero)?
_________A